Constant-area vectoring nozzle

ABSTRACT

A jet nozzle to vector the jet about a single axis. The outlet is bounded on two opposite sides by swingable outer deflecting vanes, and a central swingable vane is mounted midway between the outer vanes. Linkage connects the three vanes for movement such that the nozzle remains convergent and of substantially constant area over the range of travel of the vanes.

United States Patent Hayes et al.

[ 5 Feb. 8, 1972 [54] CONSTANT-AREA VECTORIING NOZZLE [72] Inventors:Charles F. Hays, Indianapolis, Ind.; David R. Steffey, Allestree, Derby,England [73] Assignee: General Motors Corporation, Detroit,

Mich.

[22] Filed: July 14,1967

[21] Appl.N0.: 653,361

[52] US. Cl ..239/265.35 [5|] Int. Cl. ....B64c15/04 [58] Field ofSearch ..239/265.3S

[56] References Cited UNITED STATES PATENTS Keppus ..239/265.35

Price 1....239/26535 Kosin et al. ..239/265.35

Primary ExaminerLloyd L. King AttorneyPaul Fitzpatrick and Jean L.Carpenter [57] ABSTRACT A jet nozzle to vector the jet about a singleaxis. The outlet is bounded on two opposite sides by swingable outerdeflecting vanes, and a central swingable vane is mounted midway betweenthe outer vanes. Linkage connects the three vanes for movement such thatthe nozzle remains convergent and of substantially constant area overthe range of travel of the vanes.

2 Claims, 3 Drawing Figures PAIENTEUFEB 8 I972 3,640,469

sum 1 or 2 INVENTORS Charles 31%; 5 BY David 1?. szeffey pad ATTORNEYPAIENTEBFEH a 1972 3.640.469

WEE? E OF 2 ATTORNEY CONSTANT-AREA VECTORING NOZZLE Our inventionrelates to jet nozzles for reaction engines with means for varying thedirection of the propulsive or lift jet. Such vectoring nozzles arefrequently used as a means of control of aerial and space vehicles. Ourinvention is particularly suitable for deflection of the jet of verticallift engines such as are used in certain types of vertical takeoffaircraft. In such installations, it may be desired to vector the jetfrom lift engines to control the aircraft in yaw or to translate it. Insuch an installation, it is important that the flow characteristics ofthe nozzle remain constant during such vectoring to avoid possibledisturbance of the operation of turbojet lift engines which arevectored; and thus promote stability of the aircraft, or at leastsimplification of the controls.

The principal objects of our invention are to provide a vec- .toringnozzle which has a converging characteristic and which has a constantnozzle area during variations in direction of the jet; one which issimple in structure, and one which is of minimum weight and ofconservative axial length with respect to the size of the jet engine andthe angle of deflection of the jet. A more specific object of ourinvention is to provide a variable jet nozzle having three vanesswinging about substan tially parallel axes which are so interconnectedthat they move together to deflect the engine exhaust or lift jet ineither direction and provide a convergent nozzle of constant area overthe range of deflection.

The nature of our invention and the advantages thereof will be clear tothose skilled in the art from the succeeding detailed description of thepreferred embodiment of the invention and the accompanying drawingsthereof.

FIG. 1 is an elevation view of the jet nozzle for a jet engine with avectoring arrangement according to our invention.

FIG. 2 is a transverse sectional view of the deflecting vanes taken onthe plane indicated by the line 2-2 in FIG. 3; and

FIG. 3 is a bottom view of the nozzle.

The drawings illustrate only the lower or exhaust end of the liftengine, the remaining structure of which may be of any suitable typesuch as those shown in US. Pat. Nos. 3,263,420 and 3,3 I 3,105. Theengine includes outer casing 5 which may be a turbine case or an exhaustduct therefrom, and which is cylindrical; a transition duct section 6extending from casing 5 to a rectangular terminal portion 7 of theexhaust duct. The terminal portion 7 is bounded by two parallel walls 9and by two diverging flat walls 10. An outer vane 11 (FIGS. 2 and 3) ismounted on a shaft 13 adjacent each outer wall 10. The vanes and shafts13 are carried by hinge structures 14 extending from the jet nozzle andfrom the vanes 11. An inner vane 15 is fixed to a shaft 17 midwaybetween the shafts 13, and the shaft is journaled in bosses 18 on walls9. The solid line representation of vanes 11 and 15 in FIG. 2 showstheir position for straight or nondeflected exhaust and the broken linesrepresent the position of the three vanes for maximum deflection of thejet, 20 in the particular case illustrated. The vanes may, of course,swing correspondingly in the opposite direction to deflect the jet 20 inthat direction. It will be noted that the vanes converge toward eachother so that, in the straight position, the nozzle is entirelyconverging with the throat at the trailing edge of the vanes, therebeing actually a throat at each side of vane 15. When the vanes aredeflected as shown, there is a throat between the trailing edge of vane15 and the side of the vane 1 l which is swung outwardly and between thetrailing edge of the vane 11 which is swung inwardly and the side ofvane 15. The vanes 11 converge toward the trailing edge from the axes ofrotation 13 of the vanes, and the shafts 13 are preferably parallel.

It is an important feature of our invention that the vanes are socoupled that the throat areas remain substantially constant throughoutthe range of travel of the vanes. This may be accomplished by a suitablyconstructed linkage interconnecting the vanes, the preferred embodimentof which is illustrated principally in FIG. 1. Shaft 13 of the leftouter vane as illustratecl is rigidly connected to an actuating arm 21which, in turn, is coupled to a link 22 by a pivot pin 23. Pivot pin 23lies in the plane of vane 11. Link 21 is connected to the upper end of arocker arm 25 by a hinge pin 26. Rocker arm 25 is supported by a shaft27 mounted in a rocker arm support bracket 29 affixed to the wall 9. Inthe undeflected position of vane 15, the rocker arm 25 is disposedparallel to the axis of the nozzle. Pivot pin 26 also is coupled to alink 31 in turn pivoted by a pin 32 to a bellcrank 33 affixed rigidly toshaft 13 of the right hand outer vane as illustrated. Pin 32 lies in theplane of this vane. One arm of bellcrank 33 is coupled to the piston rod34 of an actuating cylinder 36 which is mounted on a bracket 37 fixed tothe exhaust duct 5.

The linkage so far disclosed will cause concurrent actuation of the twoouter vanes in the same direction, but not to the same degree, asappears from FIG. 2. The remainder of the linkage comprises means forcausing the intermediate vane to move to such extent as to maintainequality of the two outlets on each side of vane 15. This linkage shouldcause vane 15 to move in an amount approximately equal to the average ofthe movement of the outer vanes. In one simple and preferred form of thelinkage to operate vane 15, it comprises an arm 40 rigidly fixed torocker arm 25, an arm 41 rigidly fixed to the outer end of shaft 17,these arms being substantially parallel in the centered position of vane15, and a link 42 pivoted to the ends of arms 40 and 41 coupling themfor joint movement. With the linkage illustrated, rocker arm 25 swingsin the opposite direction from arm 21 and bellcrank 33 and to a somewhatgreater extent, as it is shorter. The linkage connecting arm 25 to shaft17 acts as a reversing linkage so that arm 41 moves in the samedirection as arm 21 and bellcrank 33. Arm 41 is longer than arm 40 sothat the movement of vane 15 is less than that of rocker arm 25. Byproportioning the linkage as shown and described, the movement of vane15 will be approximately the average of the movement of the two outervanes 11 and the constants may be chosen such that the width of thethroats between the two outer vanes and the inner vanes remainsubstantially the same in all positions of the vanes, and both nozzlesremain convergent at all times.

It will be apparent from FIG. 3 that the operating and interconnectinglinkage is duplicated at the other end of the vanes so as to provide theproper accuracy of movement with the rather light structure. Theadvantages of the arrangement will be apparent if we consider, forexample, two vertical lift engines in an aircraft in which it is desiredto vector the exhaust of one engine, either to control the aircraft inyaw, or to provide a forward and backward or a lateral control ofaircraft movement. With the structures illustrated, the areas of thenozzles remain constant during the vectoring so that the performance ofthe engines is not differentially affected or compromised and lift ofboth engines will remain the same, other conditions remaining constant.The lift is not disturbed by the vectoring of the nozzle except to theextent that the lateral vector detracts from the vertical vector which,of course, will be the same for any two engines with the same degree ofdeflection.

The detailed description of the preferred embodiment of the inventionfor the purpose of explaining the principles thereof is not to beconsidered as limiting or restricting the invention since manymodifications may be made by the exercise of skill in the art within theprinciples of the invention.

We claim:

1. A jet nozzle vectoring arrangement for a reaction engine comprising,in combination, an exhaust duct terminating in a portion ofsubstantially rectangular cross section, two outerjet deflecting vanespivotally mounted on means defining substantially parallel axes atopposite sides of the said portion, an inner jet deflecting vanepivotally mounted on means defining an axis substantially equally spacedfrom the outer vane axes, the inner vane dividing the exhaust duct intotwo substantially rectangular convergent nozzles each having a throatbounded at opposite sides by a said outer vane and the inner vane, anactuator for swinging the three said vanes concurrently about theirrespective axes to deflect the jet, and a linkage connecting theactuator to the three vanes for concurrent unequal ing about the pivotaxes of the vanes, a rocker arm intermediate the outer vane arms,rotating counter to the outer vane arms, links connecting each outervane arm to the rocker arm, and means coupling the rocker arm to theinner vane.

jfggg UNITED STA fie mfibmw CERTIFICATE OF CORRECTION Patent N 3,640,469Dated February 8, 1972 Inventorfls) Charles F. Hayes and David R.Steffey It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 4, "claim 3" should read claim 1 Signed and sealed this21st day of November 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A jet nozzle vectoring arrangement for a reaction engine comprising,in combination, an exhaust duct terminating in a portion ofsubstantially rectangular cross section, two outer jet deflecting vanespivotally mounted on means defining substantially parallel axes atopposite sides of the said portion, an inner jet deflecting vanepivotally mounted on means defining an axis substantially equally spacedfrom the outer vane axes, the inner vane dividing the exhaust duct intotwo substantially rectangular convergent nozzles each having a throatbounded at opposite sides by a said outer vane and the inner vane, anactuator for swinging the three said vanes concurrently about theirrespective axes to deflect the jet, and a linkage connecting theactuator to the three vanes for concurrent unequal movement, the linkagebeing so constructed that both said nozzles remain convergent and ofsubstantially constant area over the range of movement of the vanes. 2.A combination as recited in claim 3 in which the linkage comprises outervane arms coupled to each outer vane swinging about the pivot axes ofthe vanes, a rocker arm intermediate the outer vane arms, rotatingcounter to the outer vane arms, links connecting each outer vane arm tothe rocker arm, and means coupling the rocker arm to the inner vane.